US 5,137,286 A · Permanent magnet floating shaft seal

Abstract

A seal ring is spaced radially about a rotating shaft and axially from opposed walls of a housing by permanent directional magnets mounted in the seal ring, shaft and housing. Permanent magnets are disposed about the interior surface of the seal ring and the exterior surface of the shaft, respectively, such that opposite poles lie in radial opposition affording a repelling force therebetween maintaining a radial gap therebetween constant. Permanent directional magnets are disposed on each side of the gaps between the seal ring and opposing axial faces of the housing and have like poles in opposition to one another to locate the seal ring in the axial direction. The gaps between the housing and seal ring and between the seal ring and shaft are maintained by the magnets at minimum clearance, thereby affording a non-contacting seal with well defined leakage paths.

Claims14

Dependent claims

A seal for minimizing leakage between fixed and rotatable elements comprising:

a shaft mounted for rotation about an axis, said shaft having a first permanent magnet about said shaft;
a housing disposed about and spaced from said shaft;
a seal ring in said housing about said shaft, said seal ring being spaced from said shaft and defining a circumferentially extending radial gap therewith;
said seal ring carrying a second permanent magnet at a like axial position about said shaft as said first permanent magnet and in radially spaced opposition thereto;
means for maintaining said seal ring spaced from said housing with a minimum clearance between said housing and said seal ring;
said first and second permanent magnets generating repelling forces therebetween to enable said seal ring to maintain a substantially constant annular gap between said seal ring and said shaft at each circumferential position thereabout to minimize leakage between the seal ring and shaft.

3 more elements

Dependencies are inferred from the claim text.

Permanent magnet floating shaft seal

Life of this patent

Permanent magnet floating shaft seal

Life of this patent

Abstract

Claims14